Georgia's State Security Service say police in the Caucasus country's Ajara region have arrested five men who are charged with trying to sell 1.6 kilograms of radioactive uranium-238 and uranium-235 for $3 million.

In a statement issued on April 28, the State Security Service said the five suspects were sent to pretrial detention on April 27.

The announcement comes 10 days after the State Security Service reported the arrest of three Georgian and three Armenian citizens who allegedly were trying to sell radioactive uranium-238 "for $200 million."

In January, Georgian security officials also reported the arrest of three men who were accused of trying to sell radioactive cesium-137.

Many law enforcement and nuclear experts fear that the highly radioactive materials could be used to make a dirty bomb -- a conventional explosive device that spreads deadly radioactive material over a large area.